Degreasing method for the seborrheic areas with respect to regaining sebum excretion rate to casual level

Background/aims: Sebum excreted from the seborrheic glands keeps the skin surface subtle and moist. Before determining the activity of seborrheic glands, the skin surface must be degreased to remove contamination but without provoking sebum excretion. The purpose of this study was to set up a standardised degreasing procedure for various seborrheic areas in different skin types. The method will take day‐to‐day variations into account with respect to the kinetics of refatting. Methods: The Sebumeter^® from Courage+Khazaka is used to quantify the sebum excretion. Day‐to‐day variations were measured on the forehead in groups of 12 volunteers on 2 consecutive days. The degreasing procedure was investigated by individual cleaning with alcohol compared to washing with a mild detergent followed by wipes with alcohol on the forehead. The degree of refatting was monitored until 3 h after defatting on seborrheic areas: the forehead, cheek, nose, chin and upper back. Results: There was no statistical significant difference in the variation from day to day (P<0.05), although a change in the individual skin types was observed. An individual difference in the number of alcoholic wipes needed to degrease the forehead was seen. Washing followed by several repetitions of alcoholic wipes was not sufficient for the forehead, chin and nose (P>0.05). For the cheek and upper back, it was sufficient to wash with soap (P<0.05). The time from degreasing the skin until the sebum output reached the casual level was 2 h (P>0.05). The area under the curve (AUC) indicates that individual skin types return to casual level after defatting. Conclusion: There was no statistically significant day‐to‐day variation using the Sebumeter^®. We ended up with different degreasing procedures in different seborrheic areas. Washing gently with a detergent solution and then performing three wipes with alcohol was optimal for degreasing the forehead, nose and chin. For the cheek and upper back, it was sufficient to use a mild soap. Casual level was reached after 2 h in all seborrheic areas, irrespective of level of oiliness.